1. Field of the Invention
This invention relates to the field of packaging of liquid filled flexible containers (namely bags) and their movement and guidance into a rigid protective container (usually a cardboard box).
2. Prior Art
In the beverage industry the use of thin film liquid and gas tight containers, commonly known as bags, is common. The bags often have an oxygen barrier in the thin film to protect the contents of the bag from oxygen in the surroundings. A fill/discharge spout is usually located at one end/corner of the bag. Such an unprotected flexible bag is impractical for storage and handling. It is not stable, cannot be stacked, and is difficult to grasp and hold, also the bag is not durable to any sharp corners or edges or objects which it might encounter. It is, however, less expensive than a rigid container capable of holding a similar volume. Therefore, a common practice which has evolved, is the use of such a flexible liquid filled bag in a cardboard box which protects the bag from shipping and handling hazards such as sharp objects and provides the opportunity to stack and handle the liquid in the bag just like any other commodity shipped in cardboard boxes.
Commonly, a bag is filled with liquid and the liquid filled bag is directed into the box by guiding or conveying it by various means and/or chutes. A patent by Hirschberger, et al., U.S. Pat. No. 4,760,683 provides an example of such loading.
A drawback associated with the prior art devices is that the rough handling received by the bag in guiding it into the cardboard box sometimes results in damage to the bag or placement of the bag spout in an unacceptable location. Faulty placement of the bag can cause its edges to hang out of the box and be damaged by the edges of the box. A slow moving packaging line which reduces the risk of damage is not efficient. Accelerating the process often causes the liquid filled bag to act in a generally predictable but not always consistent manner which causes the box loading process to fail and/or damage the product too often for efficient production.
During an accelerated and naturally variable loading operation, the natural tendency of a liquid filled bag is to start to roll at any point where a barrier or guide is erected to stop or influence the bag's motion. This rolling action often causes the fill/discharge spout of the bag to be displaced a commercially undesirable distance from its intended location. This displacement causes customer dissatisfaction upon tearing out a perforated portion of the box behind which the spout should be located and not finding it there.
To overcome these shortcomings in past devices, often, it has been necessary to station a person at the loader to aid in guiding the bag into the box or to finesse the bag after it has been placed in the box to decrease the likelihood of damage and spout misalignment. This repositioning is done by additional personnel who perform this repositioning while the bags and boxes move on conveyors. This repetitive motion can lead to injuries and any time there is additional rubbing movement of the bag there is a potential for bag and/or product damage. When the bag rubs against the sharp edges of the cardboard box it causes unacceptable injuries to the bag which can cause leaks in the bag and/or product rejection or returns by the consumer if not immediately identified.
Alternately, an excess clearance has been added to the box depth to assure that when the bag is placed in the box it does not extend up over the edges of the box and remains undamaged through the final box closing process.
Damage to the bag is especially critical where the beverage contained in the bag, such as wine, deteriorates with exposure to oxygen. Oxygen may enter the bag as a result of holes in the barrier layer of the film caused by the loading process.
In the prior art devices the liquid filled bag is conducted to a drop or release location. At the drop location, the bag is released into a chute or slide which is supposed to convey the bag into the box and keep the bag in a desired predetermined orientation with the box. Because of the nature of liquid in a bag and the freedom of the bag to deform to any outside or inside pressure, the movement of a bag through a chute for any distance where the bag changes direction and has the opportunity to roll can and does cause displacement of the spout and damage to edges of the bag when it touches or presses against sources of injury. When a direction changing chute is used to convey the bag, the positioning of the bag lacks the consistency required to provide a packaging system with a high quality and commercially acceptable defect rate.